The present invention relates generally to the field of control systems for lighting devices and in particular to a new and useful electronically addressable device and DMX-512 protocol addressing system for the device.
Theater lighting systems used in stage productions are often elaborate and include many different lighting devices and effects devices to produce a desired lighting combination. In recent years, many different aspects of lighting systems have been computerized to improve the ease and speed with which a lighting program for a particular stage show can be set up. While many different control systems are available for this purpose, one protocol which is generally accepted for use in theater lighting in particular is the DMX-512 protocol. DMX-512 protocol refers to a protocol standard as defined by the United States Institute for Theatre Technology, Inc. (USITT).
Presently, a DMX-512 protocol controller has up to 512 channels transmitted serially to each of any number of connected lighting system devices. Known devices each contain a manually set address circuit which identifies the particular channel or channels that the device will take instructions from the DMX-512 controller. Each of the DMX-512 controller channels has multiple levels, or amplitude settings, to produce different conditions in the connected lighting devices, whether they be dimmers, color mixers, etc. The DMX-512 controller does not produce a digital signal; that is, a binary address cannot be programmed on any one of the DMX-512 controller channels.
A drawback to the known lighting devices used with DMX-512 protocol systems is that the addresses of the devices must be set manually using DIP switches by a person having physical contact with the device. In order to change the address of a particular device, the DIP switches must be reset in the proper configuration for the new address.
When the lighting devices have been mounted on fly rods many feet above a theater stage, this can present a problem. Either the entire fly rod must be lowered to the level of the stage or a stage hand must climb up to the position of the lighting device. When the lighting devices are not mounted on movable theater equipment, but rather in a fixed spot this difficulty is increased. The address switches may be obstructed by other objects as well, including the mounting brackets for the lighting device, further increasing the difficulty of changing the address of a device.
The DMX-512 protocol control system is discussed in connection with the lighting system taught by U.S. Pat. No. 4,947,302. The lighting system is programmable with intensity changes, movements, etc., but the addresses of the lamps and other devices are not programmable.
Other types of lighting systems with digitally addressable devices are known.
For example, a lighting system with programmable addressable dimmers is taught by U.S. Pat. No. 5,530,332, which discusses the problems associated with manually set addressable dimmers and teaches a dimmer which is addressed by first entering a program mode by depressing buttons. An address is then set in the dimmer memory by using a central controller to generate the address location data and send the address to the dimmer. The address location data is a binary word.
U.S. Pat. No. 5,059,871 teaches a lighting system in which individual lamp controllers may have their addresses programmed electronically from a central controller unit. When one of the lamp controllers is placed in a programming mode, a Master Control Unit (MCU) in the central controller unit is used to generate an identification (ID) for the lamp controller. The particular ID is set by incrementing or decrementing any channel on the central controller between 1 and 31. The ID value is shown in binary code on a LED display. The ID in the lamp controller is the address used to select the lamp(s) connected to the lamp controller. The lamp controller may be a dimmer or on/off switch, for example.
A control system with programmable receivers for controlling appliances is disclosed by U.S. Pat. No. 5,352,957. The receivers may control lights, for example. The original addresses for the controlling receivers are initially set manually, but may be changed electronically once the receivers are connected to the control system. The addresses of the receivers are set automatically based on their positioning within the system, rather than by a person on an arbitrary basis.
U.S. Pat. No. 5,245,705 discloses a memory addressing system in which a central control unit sends a message signal with an address code to several attached devices over a bus interface. Devices which are encoded to accept the address code respond to the message signal. At column 6, lines 3-8, this patent indicates that the functional addresses recognized by a device may be changed using a control message. The memory addressing system is not specifically for a lighting system, but rather, is for use in a general data processing system.
Lighting systems using addressable lamps controlled by computers are also known in the prior art.
U.S. Pat. No. 5,406,176 teaches a lighting system controlled by a personal computer. The computer can address individual lamps which have pre-programmed addresses. However, changing the addresses of the lamps using the computer is not taught.
U.S. Pat. No. 4,392,187 discloses a console-controlled lighting system having addressable lights of the manual set type. The electronic address of each light is set using manual thumb switches. The console sends instructions which are interpreted by the light to which they are addressed.
A series of lighting cues can be programmed and stored in memory in each lamp of the lighting system disclosed by U.S. Pat. No. 4,980,806. The different lighting cues, or setups, can be recalled by a signal sent from a central controller. The electronic addresses of the individual lamps are not changed using the controller.
U.S. Pat. No. 5,072,216 discloses a track lighting system having individual lights with manually set address switches contained in the light housings.
None of these prior systems provides a method or system for using a DMX-512 protocol controller to remotely change or set the address of devices connected to the controller.
It is an object of the present invention to provide an electronically addressable device that can be used with a serial network control system and the address of the device can be set remotely using a central controller.
It is a further object of the invention to provide a method for using a DMX-512 protocol or other serial network protocol controller to remotely set the addresses of any number of connected devices.
Yet another object of the invention is to provide a method for remotely setting threshold and other preset values in one or more devices connected to a central controller using DMX-512 or other serial network control protocols.
Accordingly, the invention has a central controller, or code generating, system having a fixed number of control channels with at least one channel connected to an addressable device to be controlled, such as an addressable light dimmer. Multiple devices can be controlled by a single central controller using the individual channels to send control signals to connected addressable devices having their addresses set to specific ones of the channels.
Each device being controlled by the central controller has an electronic circuit which can interpret control signals. Each light dimmer has an electronic address which is set and is preferably unique to that device. The electronic address setting determines which of the individual channels of control information the device will take instructions from, while ignoring instructions on other channels.
Previously, the electronic address of addressable light dimmers and devices has been set using manual DIP switches on an exterior panel. Thus, once the device is positioned or mounted on a stage set, its address may not be easily changed if access to the device is restricted.
According to the invention, the electronic address for each device can be set electronically using a combination of keypress commands and a control signal from the central controller. The keypress commands, which may be made manually on the controllable devices or with a remote control, instruct the selected devices to enter an address set, or programming, mode.
Then, all of the control channels except for the channel that will address the device are set to zero amplitude level. That is, to set the address of the device to 30, a central controller channel 30 is the only channel not set to zero. The lone non-zero channel level is set to any non-zero level, preferably at least above a threshold level, Vt. The controller serially sends the signals for each channel to every connected controllable device. The device in address set mode decodes each channel signal and identifies the single non-zero level channel, which it then stores in a non-volatile memory, setting the address of the device to the non-zero level channel. Each device can then be returned to normal operation mode by operation of the remote or local keys on the device.
In a case where the addressable device uses more than one channel, the non-zero level channel sets the base address, and the additional channels used by the device are set as the next sequentially higher channel from the base address channel.
Alternatively, in addition to setting an address channel for the connected devices, peak and minimum limits, and other preset values, such as initial system states can be programmed with the address. The limits or preset values can be programmed using specific blocks of controller channels, or using channels following the non-zero channel setting the address. The addressable devices contain circuitry and software needed to store and interpret the signals received from the controller.
Thus, using the invention, several addressable devices can be positioned or mounted, as on a theater stage and using a combination of remote controls and the a controller, such as a DMX-512 controller, the addresses and preset limits of the devices may be set easily from a distance without disturbing their positioning.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.